@article{6568,
  author = {H. van der Hart and K. Meyer and Chris Greene},
  title = {Double photoionization and ionization excitation of the metastable helium S states},
  year = {1998},
  journal = {Physical Review A},
  volume = {57},
  pages = {3641-3645},
  month = {Jan-05-1998},
  issn = {1050-2947},
  doi = {10.1103/PhysRevA.57.3641},
}